1. Field of the Invention
The present invention relates to a shearing tool and, more particularly, to a pruning hook for a gardening purpose to shear branches or leaves at a higher location.
2. Description of the Related Art
A conventional pruning hook in accordance with the prior art shown in FIG. 6 comprises an extension shank 60, a blade unit 70 mounted on a front end of the extension shank 60, a driving unit 80 mounted on a rear end of the extension shank 60, an elastic member 81 mounted on the driving unit 80, and a linkage 61 connected between the blade unit 70 and the driving unit 80. In operation, when the driving unit 80 is pressed by a user's hand, the driving unit 80 is operated to drive the linkage 61 which drives the blade unit 70 so as to perform a cutting action. On the contrary, when the pressing force applied on the driving unit 80 is removed, the driving unit 80 is driven by the restoring force of the elastic member 81 to open the blade unit 70 so that the blade unit 70 is opened at a normal state by the elastic force of the elastic member 81.
However, the driving unit 80 is driven by a pressing force applied by the user's hand to drive the blade unit 70 so that the blade unit 70 has a smaller shearing force to perform the cutting action and cannot cut a larger object easily. In addition, the user's hand needs to press the blade unit 70 successively so as to drive the blade unit 70, thereby easily causing pain to the user. Further, the linkage 61 is connected between the blade unit 70 and the driving unit 80 to directly transmit the force from the driving unit 80 to the blade unit 70, so that the blade unit 70 is not operated in an energy-saving manner.